These Trendtimes9 Piece Filter are replacement filters for a Standard Size Reverse Osmosis Water Filtration System. They are made from best martial to offer fresh, clean, and safe filtered water in your home. It protects you from the harmful effects of lead, heavy metals, chlorine, chemical contaminants. You and your family will have years of enjoyment and good health with it. High Quality: Compatible with 5-Stage Reverse Osmosis System & Easy to replace and install by unscrewing the cases and inserting the filters All water-contacting parts are made of food grade plastic for safety; Replaces old filters without buying complete kit for saving money GAC carbon filters and CTO carbon block filters reduce chlorine or harmful chemicals, bad taste and odor, ensuring water’s nature color & normal smelling PP sediment filters to remove suspended solids down to 1 micron in size, such as large particles, dirt, silt, sand, rust, also prevent the membrane and system from clogging Product Details: 1st Stage-Polypropylene filter: High-Grade 1 micron high-capacity polypropylene sediment filter remove larger particles & suspended matter such as dirt, silt, rust, sand from water. Protects and extends the life of the membrane and system Recommend replace every 6 months, varies depend on the water source quality Standard Size(Dia.xH): 2 7/16" x 10" (6.2 x 25.4 cm) 2nd Stage-GAC Activated Carbon: Remove of deep-seated particulate impurities,sludge,rust other suspended matter, color adsorption, odor, pesticides, detergents and other organic pollutants Recommend replace every 6 months, varies depend on the water source quality Standard Size(Dia.xH): 2 7/16" x 10 1/4" (6.2 x 26 cm) 3rd Stage-CTO Coconut Shell Carbon Block Filter: Forceful remove pesticide residues in water, water pollution odor of ozone, chlorine removal of residual heavy metals, rate if 99% Recommend replace every 16 months, varies depend on the water source quality Standard Size(Dia.xH): 2 7/16" x 10" (6.2 x 25.4 cm) Also In The Box: 3x Polypropylene Sediment Filters 3x GAC Coconut Shell Carbon Filters 3x CTO Coconut Shell Carbon Block Filters 1x Manual